For these nuclei, the transitions GT_Īnd the reactions (p,n) are the primary experimental tools used to obtain theĭistribution of intensities, but the reaction ( 3He,t) has served as anĪlternative experimental tool. Particularly nuclei in the A = 40 - 48 region. We focus our attention on GT transition intensities in the 2p1f shell and The isoscalar pairing channel as it is expected to be especially important for The nuclear shell model in several recent works (14),(15). Possible importance in N ≈ Z nuclei has also been studied recently in the context of Hartree-Fock-Bogolyubov (HFB) 12, 13 to include the proton-neutron pairing channel. The earliest work considered the extension of mean field techniques like BCS or Light nuclei has been studied in recent years with a variety of formalisms. Momentum and thus exploit the short-range nuclear force. = 1), in both of which the neutron and proton can have net zero orbital angular Proton-neutron pairing can arise in two channels, isoscalar (T = 0) and isovector (T Important to also consider the possible importance of proton-neutron (pn) pairing. Microscopic foundation for the use of the pairing plus quadrupole Hamiltonian, whoseįor a meaningful description of relatively light nuclei with N ≈ Z, however, it is The dominance of the quadrupole-quadrupole interaction in the particle-hole channelĪnd isovector (J = 0) pairing in the particle-particle channel serves as the We then turn to the important role of Gamow Teller transitions in nuclear structure. Here is on the theoretical developments in the last few decades. While some experimental results are mentioned, the emphasis Process whose neutrinoless mode, if observed, would shed light on the understanding Nucleosynthesis in astrophysical environments and in double beta decay, a rare We begin with a description of its role in Particular Gamow-Teller transitions, in the various areas noted above in which it is In this work, we describe the relevance of charge-exchange reactions, and in Experimental measurements for such reactions at angles close toĠ O and with an incident energy above 100 MeV/nucleon provide valuable Possible to access GT transitions for large values in energy without the Q value On the other hand, with charge-exchange (CE) Strength B(GT) can be obtained from □ decay studies, but with excitation energies Into a neutron, and GT_ in which a neutron is changed into a proton. There are two types of GT transitions GT + in which a proton is changed Furthermore, they are very useful for the They play a key role in the βĭecay and electron capture processes that arise in stellar evolution 5, 6, in the double beta decay process 7, 9 and in neutrino nucleosynthesis 9 - 11. Gamow-Teller (GT) transitions provide an important and useful tool in the exploration Keywords: Charge-exchange Gamow-Teller isovector and isoscalar pairing quadrupole-quadrupole interaction shell model fp shell Transition properties and on the corresponding energy spectra, which are The two pairing modes is found to exhibit different but systematic effects on GT The simplified Hamiltonian is highlighted. To avoid producing spurious results for the ground state spin and parity with Suppress the isoscalar pairing mode when treating nuclei with a neutron excess Includes a comparison with experimental data as an important theme. Rotational properties of the various nuclei involved in the decays. Impacts the behavior of GT transitions and the corresponding energy spectra and Optimal set of Hamiltonian parameters for the model, to provide a starting pointįrom which to vary the relevant pairing strengths and thus assess how this Well as both isoscalar and isovector pairing interactions. Use a schematic Hamiltonian that contains a quadrupole-quadrupole interaction as This subject, we report a systematic shell model study aimed at providingįurther clarification as to how these pairing modes compete. Following a summary of the progress made in recent years on Playing a role in competition with the isovector pairing that dominates in Relatively light nuclei, especially in theĢ p1 f shell, where isoscalar pairing may be We then turned our focus to Gamow-Teller (GT) transitions in Manifestation of collective modes, some associated with deformation of the Quadrupole-quadrupole channels in the description of energy spectra and in the Including the central role played by the isovector pairing and the Steps in the emergence of our current understanding of the structure of nuclei, Their role in nuclear structure we first provide an overview of some of the key Gamow-Teller transitions, first to astrophysical processes and double betaĭecay, and then to the understanding of nuclear structure. We describe the importance of charge-exchange reactions, and in particular
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